Digital BW, The Print

I posted earlier a query about Gimp-Print (an open-source Linux 
printer driver/RIP that is now able to run on OS X Jaguar). I was 
able to track down Robert Krawitz, who is part of the development 
group, with some specific questions that might be of interest to the 
list.

Is this as interesting as I think it is? An open source downloadable 
RIP that runs on a Mac and allows individual control of each ink 
position, density and gamma, as well as a choice of dithers? 
Including a 16 bit pass through option? May be clunky at the moment, 
but the price is right, and he thinks what I want-quad black printing 
capability- is "quite interesting".

I asked if I could share his response with a couple of lists, and he 
replied "Please do."

See also http://gimp-print.sourceforge.net/index.php3 and related pages.



>Date: Thu, 17 Oct 2002 19:39:30 -0400
>To: Robert L Krawitz <rlk@...>
>From: Bruce Kinch <pvx@...>
>Subject: Re: Gimp-Print
>Cc:
>Bcc:
>X-Attachments:
>
>Hello Robert-
>
>Thanks for the prompt and informative reply reply.
>>
>>    I have some questions re using Gimp-Print with Mac OS X
>>    (Jaguar). If there is a support system in place, this might better
>>    be directed there, but as you seem to be intimately involved (and
>>    in the Boston area?) I'm contacting you directly.
>>
>>This isn't really a support question; it's more appropriate for me
>>directly, or for the gimp-print-devel@... mailing list
>>(the development team and other interested people).  Your requirements
>>here are quite interesting.  Do you know Richard Wolfson, by any
>>chance?  He and I have done some experiments (also with a 7000, but
>>not with quadtone inks at the time).
>
>The name is vaguely familiar, don't believe I know him personally.
>
>>
>>    I'm in Boston (I teach photography at the Art Institute), and have
>>    begun doing photographic inkjet printing for several years. I
>>    specialize in B&W printing, using quad black pigment inks rather
>>    than standard color dye inks. (The commercial process is called
>>    Piezography). I recently purchased an Epson 7000 24" large format
>>    printer which I would like to set up for this purpose. Most of the
>>    industry is based on Windows RIPs, and I work on a Mac.
>>
>>One such process is called Piezography; MIS also makes quadtone inks.
>
>Yes, I've used both.
>
>>
>>    My curiosity about Gimp-Print was raised by the announcement that
>>    an OSX version was available. In browsing through your web-site,
>>    several aspects were of interest-the dither choices, ink
>>    density/gamma controls, and (in 4.3 I think) direct control of the
>>    individual inks?  The quad-and hex-black approach substitutes gray
>>    inks for the color positions, so the work flow benefits from this
>>    kind of control. The Epson driver makes this difficult. SO a few
>>    questions-
>>
>>4.3 offers direct control of the individual inks, but there's only one
>>test application in the package that allows actually doing this (it's
>>called a test pattern generator, but it's also capable of printing an
>>image file in a special 16-bit format).  Unfortunately, none of the
>>really juicy stuff is yet available on OS X; if you're willing to
>>experiment with Linux, it can be done.
>
>I'm afraid that is beyond my level of expertise...
>
>>
>>There's also a workflow Regis Rampnoux has devised for printing
>>grayscale images from the GIMP, which is analogous to Photoshop.  You
>>may be able to adapt his workflow.
>
>This does sound interesting.
>
>>
>>    Can one print from within Photoshop, or is Gimp-Print freestanding?
>>
>>    Is Gimp-Print capable of printing directly from CMYK files, or does
>>    it generate CMYK from RGB files only?
>>
>>It's capable of printing CMYK.  This is available in both 4.2 and
>>4.3.  I think the version of CUPS on OS X 10.2 is recent enough, but
>>I'm not certain (versions of CUPS prior to about 1.1.14 converted CMYK
>>files to RGB, to apply a rather primitive profile, and then converted
>>back to CMYK!  Needless to say that's not quite the right idea).
>>
>>Both 8 and 16 bit CMYK inputs are available.  The 8 bit CMYK input is
>>gamma and density corrected; the 16 bit input is completely raw (no
>>corrections at all for paper type, resolution, etc. -- the idea is
>>that the rest of your workflow does all of that).
>>
>>    Is there separate control over CMYK output channels, or separate
>>    control of the individual C and light C, M and light M inks
>>    themselves?
>>
>>Both options are available in 4.3; in 4.2, only the CMYK input is
>>available.  The printer-specific output in 4.3 is 16 bits per channel
>>only, and only Epson printers currently implement it.  CUPS (and
>>therefore currently OS X) can't use either 16 bit input mode.
>>
>>    Is there any way or place I could see examples of Gimp-Print
>>    output, especially with the large format Epson printers?
>>
>>I can certainly give you some samples.  Perhaps you and I can get
>>together some time; I could bring my laptop over, which has everything
>>needed on it.
>
>I would very much like to do that. My 7000 isn't up and running yet, 
>but I may have access to another.
>
>Your comments are intriguing. Would you mind if I shared them with 
>the digital printing lists I receive? You might get some interesting 
>queries.
>
>Regards,
>
>Bruce
>--
>
>Bruce C. Kinch
>Associate Professor of Photography
>The Art Institute of Boston at Lesley University


-- 
PS: Please note new ISP address, pvx@...

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